Engine starting apparatus



April 30, 1940. fH. BAER ET AL ENGINE STARTING APPARATUS Original Filed Aug. l, 19255 A INVENTORS. 70 Ward Ba ef /l//a/'f/'n J Hime cm `Y l 4JH l Patented Apr. 30, 1940 UNITED vS'IK'ATIVES PATENT OFFICE A v l n '2,199,328-A l Y ENGINE srAnTING APPARATUS Howard Baer, JerswY city, N. J., and Martin J. Finnegan, NewYork, N. Y., assignorst'o- Eclipse' Aviation Corporation, East Orange, N. J., a .corporation ofI New Jersey Original application August 1', 1935, Serial No.

34,286-, now Pat'ent'No. 2,154,555, dated April 18,v 1939; -Divided and this application February I2, 1937, Serial No. 125,496

2 claims. (ci. iaiavi l Thisl invention relates to engine starters, and particularly' to` those ofthe type having an engine engaging member which'is movable t'o'engagging-position to impartinitial rotary movement to the engine crankshaft; and subsequently retracted, or demeshed when the crankingeffort is discontinued'.

An object of-v the invention is to provide means for holding the engine: engaging member in engineengaging position until the engaged enpressure, as in ther embodiment illustrated in the accompanying drawing, the holding means for the engine engaging` member preferably takes the formr of a mesh controlling piston movable in response to application of the uid pressure, and having pressure trapping means associated therewith to hold the piston (and hence the engine engaging member) in the effective position until the engaged element of the engine runs ahead of i. e., overruns-the engine member of the starter.

In the illustrated embodiment the starter -is shown as of the type including a piston (distinct from the mesh controlling piston above described) reciprocable within a lfluid receiving chamber, the motion of the piston being converted into rotation of the engine engaging member by suitable translating mechanism; but it is` Fig. 1 is'alongtudinal .sectional view of a device embodying the invention;

Fig. 2 is a 'transverse sectional view along line 2*-2 of Fig. 1u; and

Fig. 3 is a transverse sectional view along line 3-3 of Fig. 1.

With reference to the-drawing, and more particularly to Fig. l, the piston and engine starting gear unit comprises a body member I having a ange I2 by'which it is secured to the engine crankcase I3 as by bolts I4, the ange being conveniently of a size standardized for aircraft engine starters. The engine crankshaft, or other drive shaft (not shown) is provided with an enginey jaw II engageable by the starter jaw' I5' as will be later more fully described.. Screw 'threaded in a` quickly detachable' manner tok an annular iiange I6 integral .with the body III is a cylinder Il having a closed'head I8,

and slidably ttedwithin the cylinder is a piston comprising the head I9 secured to the rotatable cylindrical piston body 20, the piston body 20 and the main starter body I0 being provided with cooperating helical grooves 2'I and 22. .A sleeve 26 is internally drivably connected with the piston body 26 vby splines 21 and 28 which permit the axial travel of the piston body relative to the sleeve, but restrainthese two parts to unitary rotation. An anti-friction thrust bearing 29 is preferably interposed between the end of the sleeve 26 and a nose piece 30.

The starter jaw I5 is splined for limited axial travel within a second'sleeve 3| and is normally 'retained in theposition shown by a central rod portionf53 constituting a' slide` valve adapted to 'close the port 54 'in cylinder I8 when the piston moves `forward -to a suflicient extent to mesh the parts I5 and I I, such forward movement being yieldedlyfopposed by the spring 56. As shown the cylinder 35y is received within the borev of the externally threaded extension 6I formed centrally of the piston head I9 and engageable with a correspondingly Yinternally threaded sleeve 62 terminating in afportion 63 of reduced diameter constituting `the inner race of an overrunning clutch; 64, the outer race being constituted `by the extending socket 660i an internally splined sleeve 3I previously described. This sleeve 3| constitutes lthe' inner race of a second overrunning clutch 68, the outer race of which is constituted by the previously described sleeve 26. t Exhaust ports 36 are uncoveredby the piston at the rleft-hand end of its stroke and an exhaust ring 31 preferably collects thedischarge so that ,it may be led away to any desired point bya suitable pipe 38. A spring 39 normally maintains the piston at the right-hand end of its travel as shown, andthe piston is preferably equipped with a pair of piston rings 4I. The cylinder head I8 is provided with a pipe 46 which may be connected to the breech of a cartridge firing mechanism, as in Fig. 3 of our Patent No; 2,154,555

granted April 18, 1939, or to a pressure chamber, as in Fig. 2 of said patent.

In order to hold the piston head I9 against rotation, a plurality of rods 9i are caused to extend Athrough apertures in the piston head, the outer end of the rod being fixedly secured in the stationary head I8. One of these rods 9| is apertured as indicated at 92 and is also longitudinally bored to permit passage of fluid into the pipe 78 from the space to the right of the piston head IS when the latter has advanced to the left to a sufcient extent to uncover the said port 92.

This application is a division of application Serial No. 34,286, filed August 1, 1935, which has matured into Patent No. 2,154,555, issued April 18, 1939.

What is claimed is:

1. In a device of the class described the combination with an engaging member, of actuating means including a reciprocable part operative in one position to hold said engine engaging member disengaged from the engine, and in another position to hold said engine engaging member engaged with the engine, a fluid receiving chamber and means for supplying pressure uid to said chamber to move said reciprocable part from "said first-named position to said second position, and means for holding said reciprocable part in said second position even after the exhaust of pressure fluid from said chamber, said last-named means including a second chamber into which a part of the pressure uid enters after passing through said first-named chamber, and means movable with said reciprocable part to trap said fluid in said second chamber.

2. In a device of the class described the combination with an engaging member, of actuating means including a reciprocable part operative in one position to hold said engine engaging member disengaged from the engine, and in another position to hold said engine engaging member engaged with the engine, a fluid receiving chamber, means for supplying pressure iluid to said chamber to move said reciprocable part from said first-named position to said second position, means for holdingsaid reciprocable part in said second position even after the exhaust of pressure fluid from saidr chamber, said last-named means including a second chamber into which a part of the pressure uid enters after passing through said lirst-narned chamber, means movablel with said reciprocable part to trap said ud in said second chamber, and engine operated means engageable with said engine engaging member to return said reciprocable part to its initial position and, by the same action, release the fluid trapped in said second chamber. l

HOWARD BAER. MARTIN J. FINNEGAN. 

